This invention relates to flow admission control for a network router, switch, bridge, gateway, or any other network component which receives and then forwards data.
Computer networks, such as the Internet, are increasingly required to support transmission of one way or two way realtime data such as video and audio data. Such transmissions may serve a variety of ends, from providing health care to operating businesses to providing entertainment. In such transmissions, a sender application transmits audio or video data over a period of time (hereinafter referred to as a "flow") to a receiver application. Since computer networks are generally implemented as packet switched networks, flows are generally a string of packets transmitted over a period of time.
When transmitting a flow that represents a realtime event such as an audio or video event, the packets in the flow must be delivered in a timely manner. Since each packet contains data as to a segment of the event, each packet in the flow must arrive so that it can be processed, for audio or video broadcast to the user, immediately after the previous packet has been processed. If not, there will be a lag in the timeline of the reconstructed audio or video event. The reconstructed audio or video event would as a result appear as "jumpy" and not continuous.
One manner of implementing timely delivery of packets is to require that each packet in a flow not be delayed beyond a predetermined amount, referred to hereinafter as the "delay bound". A flow that has a delay bound may be referred to as a "bounded delay flow".